Shake a quantity of the powdered tablets equivalent to 20 mg of Astemizole with 25 ml of chloroform for 10 minutes, filter and evaporate to dryness

chromatogram obtained with solution (1) is not more intense than the spot in the chromalogram obtained with solution (2) Sulphated ash Not more than 0.1 %, Appendix 3 22.Loss on drying: Not more than 05%. determined on 1 g by drying in an oven at 105", Appendix 8 G Assay. Weigh accurately about O.S g and dissolve in 50 ml of a mixture of 7 volumes of 2-butanot and 1 volume of anhydrous glacial acetic acid Carry out Method B for non-aqueous Titration, Appendix 3 45H using 1 naptholbenzem as indicator. Perform a blank determination and make any necessary correction Each ml of 0.1M perchloric acid is equivalent to 0.02293 g of C28 H31 FN4 O. ASTEMIZOLE TABLETS Usual strength 10 mg Storage Store in well-closed, light-resist ant containers. STANDARDSAstemizole Tablets contain not less than 900 per cent and not more than 110.0 per cent of the stated amount of aslemizole. C28 H31 FN4 O. Identification A: Shake a quantity of the powdered tablets equivalent to 20 mg of Astemizole with 25 ml of chloroform for 10 minutes, filter and evaporate to dryness. The infra-red absorption spectrum of the residue. Appendix 5.J. is concordant with the reference spectrum of astemizofe or with the spectrum obtained from astemizofe RS.B The light absorption in the range 230 to 36D nm ofthe sofution obtained in the Assay exhibits maxima at about 249 nm and 206 run, Appendix 5.5.C: Carry out the method for thin-layer chrornatography. Appendix 4 6, using silica gel GF254 as the coating substance and a mixture of SJ vofumes of tofuene, 3D vofumes of dioxan, 10 vofumes of methanot and 1 vofume of strong ammonia sofution as the mobile phase Apply separately to the plate 10 ul of each of the foflowing sofutions For sofution ( 1) shake a quantity of the powdered tablets equivalent to 50 mg of Astemizofe with 10 ml of a mixture of equal vofumes of dichloromelhane and methanol for 15 minutes and filler Sofution (2) contains 0.5% w/v of astemizole RS in a mixture of equal volumes of dichloromelhane and methanot After removal of the plate, allow it to dry in air and examine under ultra-violet light (25d nm). Any secondary spot in the chromalogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) Uniformity of content Comply with the requirements stated under Tablets using the following method of analysis Moisten one tablet with 1 ml of water, add 25 ml of 2-propanot. warm on a water-bath for 15 minutes, cool, dilute to 500 ml with 2-propanoth mix, centrifuge and carry out the procedure described under Assay on the supernatant liquid beginning at the words "Measure the absorbance ."Other requirements Comply with the requirements of tests stated under Tablets Assay Weigh and powder 20 tablets Weigh accurately a quantity of the powder equivalent to about O.S g of Aslemizo]e transfer lo a 10Q-m1 volumetric flask, add 10 ml of water and about 50 ml of2-propanot Warm on a water-bath for-15 minutes, cool and dilute to volume with 2-propanot, mix and filter (Whatman 41 filter paper is suitable). Discard the first 10 ml of the filtrate and dilute 2.0 ml ofthe filtrate to 50 0 ml with 2-propanot Measure the absorbance of the resulting solution at the maximum al about 286 nm. Appendix 5 5 Calculate the content of C28 H31FN4 O from the absorbance obtained by repealing the operation using astemizole RS instead of the substance being examined and from the declared contenl of C28 H31 FN4 O in astermizole RS .ATENOLOLAtenelol is (RS)-4-(2-hydroxy-3-isopropylarninopropoxyjphenylacetamide Category Beta-adrenoceptor antagonist Dose 50 to 100 mg. daily, in 1 or 2 doses Description White or almost white powder Solubility Soluble in ethanot, sparingly soluble in water; slightly soluble in diehioromethane, practically insoluble in ether STANDAROSAtenotol contains not less than 99.0 per cent and not more Ehan 101 0 per cent of C14 H22 N2 O3. , calculated with reference to the dned substance. Identification Test A may be omitted if tests B, C and D are carried out Tests B and C may be omitted if lesls A and D are carried out A. The infra-red absorption spectrumh Appendix 5.4, is concordant with the reference spectrum of alenotol or with the spectrum obtained from atenotol RS.B The light absorption in the range 230 to 360